P1397LONG-TERM EFFICACY AND SAFETY OF ETELCALCETIDE IN HEMODIALYSIS PATIENTS WITH SEVERE SECONDARY HYPERPARATHYROIDISM

Abstract Background and Aims Currently the therapeutic strategies most frequently used in the treatment of secondary hyperparathyroidism (SHPT) are represented by vitamin D receptors activators (VDRAs) and cinacalcet. However, both drugs have side effects that limit their use. Recently, in the treatment of SHPT has been introduced the etelcalcetide, a second generation calcimimetic given intravenously (i.v.). This new route of administration could improve adherence to therapy and reduce gastrointestinal side effects. The aim of the study was to evaluate the efficacy and safety of the etelcalcetide in hemodialysis (HD) patients with SHPT inadequately controlled with traditional therapy (cinacalcet and/or VDRAs), or who had side effects with cinacalcet, or that were not adherent to cinacalcet therapy. Method For this purpose we have selected 28 HD patients with inadequate control of SHPT (PTH > 500 pg / ml; range 502-2148 pg/ml). Serum albumin-corrected calcium (sCa), phosphate (P), calcium–phosphate product (Ca x P), and PTH were assessed monthly. Baseline 19 patients were taking stable doses of active vitamin D analogs and all patients were taking phosphate binders. Etelcalcetide was administered three times a week after each hemodialysis session. The starting dose was 2.5 or 5.0 mg and then adjusted between 2.5 and 10.0 mg according to sCa and PTH levels. Treatment was temporarily withheld for sCa <7.5 mg/dl, or symptomatic hypocalcemia and was subsequently resumed at a lower dose. The primary endpoint was a PTH reduction > 30% compared to baseline levels. Results At present 12 months have passed since the beginning of etelcalcetide therapy. In most patients PTH levels were reduced immediately after the start of therapy. After 12 months we observed a reduction > 30% in 82% of patients, meanly -54% with a range between – 22% and – 81%. On average PTH levels decreased from 1167±444 to 558±310 pg/ml (P<.001). Serum calcium significantly reduced already after one month of therapy settling on stable levels from the third month onward, sCa decreased from 9.7±0.4 to 9.2±0.5 mg/dl (P<.01). However, the percentage of patients treated with calcium salts rose from 21% at baseline to 44% at F-U, mean dose at F-U 1.8 ± 0.9 g/d, while the percent of patients treated with VDRAs increased from 68% to 91%. Serum phosphate decreased from 6.4±1.4 to 4.6±1.3 mg/dl (P<.001), Ca x P decreased from 60±13 to 42±12 mg2/dl2 (P<.001). The median average dose of etelcalcetide at F-U was 6.2 ± 1.7 mg/HD, with a range of 2.5-10.0 mg/HD. Throughout the study, the only side effect was asymptomatic hypocalcemia that required the use of calcium salts. There were no gastrointestinal adverse effects. Conclusion Our results confirm that in hemodialysis etelcalcetide therapy is effective and safe in the control of SHPT refractory to conventional therapy over a 1-year treatment period.